1. Field of the Invention
The invention is directed to a key retainer system for a railway cushion car which prevents a coupler key from sliding out of a key slot in a yoke and which keeps the coupler key inside the sill. The key retainer system according to the invention comprises a key retainer mounted on a cutout on the outside of a railway car sill. The key retainer system further comprises improvements to a standard E-type cushioned yoke which permit the coupler key to extend completely through the key slots in the yoke. Mounting the key retainer on the exterior of the sill ensures improved visibility of the key retainer from outside the railway car, and allows the key retainer to be repaired and/or inspected without disassembling the coupler from the yoke or the yoke from the railway car. The exterior mounting also permits the coupler key to be inserted completely through an E-type yoke, ensuring that the key cannot be rotated out of position.
2. Description of the Prior Art
Two adjacent railway cars are joined by a coupler, which extends into a yoke mounted in a generally rectangular housing on a lower portion of the railway car known as the “sill.” The coupler is secured to the yoke by a coupler key (also called a “draft key”) which extends through aligned key slots in the coupler and the yoke.
The key is prevented from shifting or falling out of the yoke with a key retainer. The prior art systems are characterized by a stop member mounted on the inside of the yoke. In a typical prior art arrangement, the yoke is retained in the key slots with the aid of corresponding notches formed in the yoke and in the coupler key. The coupler key is inserted in a first key slot in the yoke until a notch in the key abuts a mating notch in the opposite wall of the yoke. A stop member located on the inside of the yoke swivels into position against a similar notch on a side of the coupler key opposite the first side. This is sometimes called a “blind key retainer,” because the stop member is mounted inside the yoke and is not visible, or at least not readily visible, from outside the railway car. An example of this arrangement is seen in U.S. Pat. No. 3,589,527.
The prior art arrangement has several drawbacks. From a safety standpoint, the state of the key retainer cannot be easily inspected. Even as digital vision inspection technology improves, the blind key retainer system does not lend itself to robotic digital vision comparisons. Further, because the stop member is mounted on the inside of the yoke, it cannot be easily accessed for repair, requiring removal of at least the coupler to repair the retainer system.